Question

Can someone please help me out?

Answer 1

Calculate the above formula, expressing the answer in scientific notation with the correct number of significant figures:

Answer 2

hint:
\[\Large 1 \times {10^{ - 3}} = 0.001\]

Answer 3

and:
\[\Large 3.61 \times {10^{ - 3}} = 0.00361\]

Answer 4

from your attachement I see this computation:

\[\Large \left( {8.86 + 1.0 \times {{10}^{ - 3}}} \right) \div \left( {3.61 \times {{10}^{ - 3}}} \right)\]
am I right?

Answer 5

Yea you are right. I accidentally read the sign wrong. I was suppose to divide not add. So I should get 2.45429362881 right?

Answer 6

I got:
\[\Large \left( {8.86 + 1.0 \times {{10}^{ - 3}}} \right) \div \left( {3.61 \times {{10}^{ - 3}}} \right) = 2.454 \times {10^3}\]

Answer 7

Do I need the full number or should I just shorten it to 2.454?

Answer 8

I think that we have to take at least 3 significant figures, so our result will be like below:
\[\Large 2.45 \times {10^3}\]

Answer 9

What exactly are the significant figures? I was confused on that part.

Answer 10

the significant figures are 2, 4, and 5

Answer 11

another example:
if we have a number like below:
1.0025
then the significant figures are:
1, 2, and 5

Answer 12

whereas, if we have this number: 1,200
then the significant figures are 1 and 2

Answer 13

So the signification figures would the answer to that part be 3? Or would the answer to that part be 2, 4, and 5.

Answer 14

if we have this number:
0.0025
then the significant figures are 2, and 5

Answer 15

your answer, is:
\[\Large 2.45 \times {10^3}\]

Answer 16

So with scientific notation you only go 2 digits after the decimal right? I thought the answer was 2.454 x 10^-3. Or am I wrong on that part?

Answer 17

when we have a decimal point, the significant figures are the figures at the left and at the right with respect to that decimal point

Answer 18

so, the number 2.454 x 10^-3 has four significant figures

Answer 19

please, wait,
is your computation an experimental measure?

Answer 20

I'm not sure what you mean on computation or experimental?

Answer 21

since 1*10^-3 has only one significant figure, then we have to rewrite our result with one significant figure, so your result is:
\[\Large 2 \times {10^3}\]

Answer 22

I was just wondering on the scientific noation is both 2.45 and 2.454 both correct. It doesn't matter how I state it. Only difference is how many significant figures their are.

Answer 23

2.45 has three significant figures, whereas
2.454 has four significant figures

Answer 24

as a general prescription, we have to round off our result like the most inaccurate measure.
Now our most inaccurate number is 1*10^-3 which has only one significant figure.
So we have to round off our final result to one significant figure, so we get:
\[\Large 2 \times {10^3}\]

Answer 25

I'm confused on how I'm suppose to state my answer. How should I write it?

Answer 26

it is simple, your measure has to be written like below:
\[\Large 2 \times {10^3}\]
which has only one significan figure, and such significant figure is 2

Answer 27

I have rounded off 2.454... to 2

Answer 28

please sorry, I see that the most inaccurate number is:
1.0 *10^-3
which has 2 significant figures, so we have to round off our result to 2 significant figures, so your result is:
\[\Large 2.5 \times {10^3}\]
I have rounded off 2.454... to 2.5
and 2.5 *10^3 has 2 significant figures, namely 2, and 5
Sorry again, for my error

Answer 29

more explanation:
a number like this one:
1.0
has two significant figures, namely 1 and 0

Answer 30

Do I have to round when stating my answer? Does it matter how I state my answer also?

Answer 31

yes! since when you do a computation, using some formula, the result which you get, can not be as accurate as the most accurate measure

Answer 32

as a general prescription, the result which you get from a computation has to be as accurate as the less accurate measure

Answer 33

So how many digits should I state in the answer? Should I round it or not? I normally don't round it unless the question states to do so.

Answer 34

yes! you have to round it, like below:
\[\Large 2.5 \times {10^3}\]

Answer 35

So is the answer is 2.5 x 10^3 or 2.5 x 10^-3 @Michele_Laino ? Do you need to take the - off with scientific notation? The original question had a -3 so I wasn't sure. Also for the significant figures there's two of them right? 2 and 5.

Answer 36

yes! the significant figures are 2 and 5, and the right result is 2.5 x 10^3

Answer 37

Thanks for all your help @Michele_Laino